Chair of Food Science and Technology, Estonian University of Life Sciences, Kreutzwaldi 1 Tartu Estonia 51006.
Chair of Food Science and Technology, Estonian University of Life Sciences, Kreutzwaldi 1 Tartu Estonia 51006.
J Dairy Sci. 2022 May;105(5):3846-3860. doi: 10.3168/jds.2021-20420. Epub 2022 Mar 2.
Although "zero waste" valorization concepts are gaining increasing attention, colostrum, a byproduct of milk production, remains underused due to technological challenges. Information about the fat fraction and the size of fat globules is needed to address these challenges, but such information is currently lacking. This study aimed to fill this gap in the knowledge by measuring the size distribution of bovine colostrum fat globules (CFG) and analyzing its relationships with postpartum milkings, parity, and fatty acids (FA) profile. Four sequential postpartum colostrum samples were collected from 44 cows and analyzed for the abovementioned parameters. The results indicated that CFG size increases almost twice during postpartum milkings (from ∼5 to ∼10 µm), whereas lactation has little, if any, effect on CFG size. The FA profile analyses showed that the content of most FA in the fourth postpartum milking was different from the previous milkings. The correlation analyses between CFG size and FA profile also demonstrated that the fourth milking was clearly distinguishable from the first 3 postpartum milkings. For example, the saturated FA content from the first 3 milkings had a positive correlation with smaller CFG (and a negative correlation with larger CFG), whereas the fourth milking demonstrated no correlations. Based on these CFG size and FA profile analyses, the results of this study suggest that the first 3 postpartum milkings can be considered as colostrum, whereas the fourth milking represents transition milk. Information about CFG size distribution enables modification of the FA profile of colostrum products and the ability to create better valorization technologies for colostrum-based food and feed supplements.
虽然“零浪费”的增值概念越来越受到关注，但由于技术挑战，乳牛初乳作为牛奶生产的副产品仍未得到充分利用。为了应对这些挑战，需要了解脂肪部分和脂肪球的大小，但目前缺乏这方面的信息。本研究旨在通过测量牛初乳脂肪球（CFG）的大小分布并分析其与产后挤奶、胎次和脂肪酸（FA）谱的关系来填补这一知识空白。从 44 头奶牛中收集了 4 个连续的产后初乳样本，并对上述参数进行了分析。结果表明，CFG 大小在产后挤奶期间增加了近一倍（从约 5 微米增加到约 10 微米），而泌乳对 CFG 大小几乎没有影响。FA 谱分析表明，第四次产后挤奶的大多数 FA 含量与前几次挤奶不同。CFG 大小与 FA 谱的相关分析也表明，第四次挤奶与前 3 次产后挤奶明显不同。例如，前 3 次挤奶的饱和 FA 含量与较小的 CFG 呈正相关（与较大的 CFG 呈负相关），而第四次挤奶则没有相关性。基于这些 CFG 大小和 FA 谱分析，本研究结果表明，前 3 次产后挤奶可以被认为是初乳，而第四次挤奶代表过渡乳。CFG 大小分布的信息可以改变初乳产品的 FA 谱，并为初乳为基础的食品和饲料补充剂创造更好的增值技术提供能力。
